The present invention refers to a brewing device for a coffee maker, comprising a brewing chamber adapted to receive a coffee powder portion and constituted by an upper brewing chamber portion and a lower brewing chamber portion. The lower brewing chamber portion includes a chamber for receiving the coffee powder portion, and the upper brewing chamber portion includes a closure element adapted to close the chamber in the lower brewing chamber portion.
Such brewing devices are used both in manually operated coffee makers and in fully automatic coffee makers. The manually operated coffee makers usually comprise a coffee powder holder that can be attached to the coffee maker by means of a bayonet fixing. Thereby, two types of coffee powder holders are in common use: First, coffee powder holders adapted to receive the loose coffee powder, and second, coffee powder holders adapted to receive a coffee powder cartridge. For piercing of such coffee powder cartridges, the brewing head of the coffee maker may comprise a grating whose exposed front surface is provided with a plurality of acute projections. These projections penetrate the cover of the coffee powder cartridge once the holder with cartridge is inserted into the coffee maker. For piercing the bottom of the coffee powder cartridge, the bottom of the cartridge holder is provided with acute projections as well. As soon as pressurized brewing water is fed into the interior of the coffee powder cartridge, the bottom of the cartridge is pressed against these acute projections under the influence of the hydraulic pressure in the cartridge and the bottom of the cartridge is pierced. Such a coffee maker is disclosed, for example, in the document EP 0,521,187.
Moreover, brewing heads for coffee makers are known in which no cartridge or coffee powder holder in the above mentioned sense is provided; rather, the two brewing head portions are pivotable in relation to each other.